I commented on this a number of years ago, and I still think the same way.
I am happy with deprecating legacy pools, but I think it is also important to be able to redeem my Zcash in the future from a pool if I can prove I control the keys. Even if this were a separate tool or an offline process that potentially takes weeks/months.
I agree that most of these coins are probably due to lost keys etc. But some may simply be long forgotten wallets.
Thought experiment, I bought/mined Zcash in early days, keys stored on an old computer. Stepped away from crypto due to disillusionment/price decline. Get on with life. Hear about Zcash in mainstream media many years later which triggers the memory of those early days. Boot up the laptop, still have the keys, result, try to access my Zcash, no luck, they’ve been destroyed. Tough luck?